Heat resistance grade code, from low to high temperature: Y A E B F H C
Heat resistance grade Maximum allowable working temperature (℃) Brief description of insulating materials equivalent to this heat resistance grade
Y 90 Insulation structure composed of unimpregnated cotton yarn, silk and paper or their combination
A 105 Insulation structure composed of impregnated or immersed in liquid dielectric (such as cotton yarn, silk and paper in transformer oil or their combination)
E 120 Insulation structure composed of synthetic organic film, synthetic organic enamel and other materials or their combination
B 130 Insulation structure composed of mica, glass fiber, asbestos, etc. bonded or impregnated with suitable resin, coated, and other inorganic materials, suitable organic materials or their combination
F 155 Insulation structure composed of mica, glass fiber, asbestos, etc. bonded or impregnated with suitable resin, coated, and other inorganic materials, suitable organic materials or their combination
H 180 Insulating structures composed of mica, glass fiber, asbestos and other materials or their combinations bonded or impregnated with suitable resins (such as silicone resins)
C 180 and above Insulating structures composed of mica, glass fiber, asbestos and other materials or their combinations bonded or impregnated with suitable resins, and mica, ceramics, quartz and other materials or their combinations that have not been impregnated.
